Why & How to Build a Piezo Preamp for your Cigar Box Guitar / Preamp for Contact Mic

[@psycheopera]

Hello Everyone! If you built the piezo preamp from this video, then you'll be interested in this info. I ran into a brilliant video by Paul McGowan from PS Audio that explains why this piezo preamp reduces high frequencies. According to McGowan, the DC blocking electrolytic capacitors are stealing our high frequencies! He does mention a solution in his video; check it out: kzbin.info/www/bejne/g6SyaXSresylhZosi=jkX-r0cYIiMiJKkk Also, A fellow maker (shout out to Klaus) alerted me to the option of changing out the bleed resistor to reduce sub bass and low bass. With the right resistor value, we may not need the passive HPF I built in my latest video: kzbin.info/www/bejne/sHm8cmCMmZuBoa8si=pBGhTWLRuVUDm_jh With this information, I look forward to tinkering with my preamp some more so that we get the best sound possible from our cigar box guitars, and, of course, I will share the results of my tinkerings here on KZbin. Cheers! - Dr. Liza Seigido

[@rayclark6596]

You can bypass the power switch by using a stereo guitar jack. The ground side of the battery is attached to the "ring" terminal for the jack. When the guitar (CBG) is unplugged, open circuit to battery. Plug in, and your battery supplies power to the circuit. It's typical wiring for all acoustic electrics.

[@psycheopera]

Wow!!! Thank you so much for the tip!!!! I will try this mod and may produce a short video about it. May I tag or acknowledge you in the video, or would you prefer to remain anonymous? Thanks again! 😀✨

[@schneidp20]

Thanks! The preamp is night and day difference in the fullness of the sound. I was ready to chuck the piezo altogether before building this preamp. I did the sharpie pcb which is mind numbingly simple. It's enclosed in a small aluminum stomp box enclosure. And I did the stereo input jack to double as the on/off switch. Thanks again!

[@psycheopera]

Hey there!✨ I'm really happy that this video was helpful to you! Bravo for including the stereo jack on/off switch! I'm looking forward to trying that when I update my preamp.🔥 I'm a big fan of this preamp, but I'm on a mission to make it even better. Take a look at this post to see what's coming up next for this piezo preamp: kzbin.info/door/4OMtVX9uQzowxCLQWqcaQgcommunity?lb=Ugkx6FE7jb1gS_WIJQ-wmj13Gfi_-8qJr3Lb (You may need to copy and paste the URL into your browser's address bar to access the referenced post.) Thanks for taking the time to check out my work!💖

[@Da_Publick]

I don't have the space (can you imagine?) or the inclination to build one. But I feel thoroughly enlightened by this video. There are a _bunch_ of manufacturers selling CBG's with piezo pickups, who say nothing about the need for a piezo preamp.

[@psycheopera]

Hi, thanks for checking out my video! ✨💜 Some instrument manufacturers have the pre built into the instrument without indicating it. If instruments need batteries, then you know they have built in preamps. A preamp will allow you to enjoy the true acoustic sound of the instrument. But to clarify: a piezo pickup will work without a preamp, but you will likely encounter tone and volume issues. I personally don’t record my CBG direct into an audio interface without my preamp. However, when I’m performing casually out in craft markets, I simply mask the tone and volume issues by playing with gain and distortion settings on my portable guitar amp without using my preamp. 🔥 I hope this was helpful.🙏 let me know if you have any questions.🎸

[@Da_Publick]

@@psycheopera Yes, and thanks again, it was very helpful. Now I understand why a preamp would _not_ be necessary with these CBG's. The company is a roots style operation, so they also make Cigar Box amps that use a 2.5 watt Artec circuit; the 'DIY special.' It's very similar to a Pignose. I'll go out on a limb that this kind of amp wouldn't have any issues with piezo amplification.

[@psycheopera]

My pleasure!✨ Wow, that sounds like an interesting company. I would love to see one of their cigar box amps. Do you remember their name? Are they on KZbin?

[@Da_Publick]

@@psycheopera Yep, it's C.B Gitty. I'm sorry for making you ask, but some folks are funny about listing the names of companies in their channels. 😂

[@Da_Publick]

@@psycheopera They've got a youtube channel.

[@lauram.sanchez-ramirezlife1006]

This haiaaaasrrr! I Love it!! ❤enjoying my guitar!!!! Like you have no idea!!!

[@psycheopera]

Thanks so much!!!! That's one of my favorite wigs. 😁 So glad you're enjoying your CBG!!!!! ✨❤️🎶

[@user-ed3ul7bm5p]

Everyone's situation may vary but I've had great results using a piezo pickup in passive guitar circuits, or straight to a jack. No issues whatsoever when using pedals or only an amp too.

[@psycheopera]

Hi! Thanks for checking out my video. ✨ True, situations may vary. I usually don’t use my pre with my amps with tone control. For me, it’s a must with my TC helicon, zoom and recording direct into my computer. Also…quick update: since the production of this video, I’ve fixed problems with my pre and now I can use my cbg with my tc helicon play electric with good results 👍 The pre still needs to undergo more improvement to get the truest sound from my cigar box guitars. I’ll be swapping its drain resistor to cut some sub bass and adding some bypass capacitors to get the highs my guitars are actually producing. It’s been a journey and I hope you’ll stay tuned to see and hear the improvements ✨ 🎸

[@bradmasiowski5233]

Hi. I believe the 4.7 microFarad cap is the one that blocks the DC component of the signal. Otherwise the info that you provided was all good. I look forward to using this design in my resonator guitar mod. Thanks

[@psycheopera]

Hi! Thanks for the info! ✨ Through research and with the help of fellow audio electronics enthusiasts like you, I'm making plans to mod this pre to improve its frequency balance. It's a good-sounding pre, and it is worth building, but it does translate too much sub-bass from the piezo. I currently have to use it with an external high-pass filter. Also, it is high-frequency deficient because of the electrolytic caps. I've learned that by switching out the bleed resistor and installing bypass film caps parallel to the electrolytic caps, I can eliminate unwanted sub-bass and get back my sparkly high frequencies. I will produce a video when I've made and tested these mods. I am currently working on other projects, so it may be a while until I can tackle my preamp mod, but I hope you'll keep an eye on my channel for my piezo preamp update video. Have a beautiful day!😀 -Dr. Liza Seigido

[@PrincessFionaYT]

Pure awesomeness.

[@psycheopera]

Thank you💜 So glad you enjoyed it🔥✨

[@psycheopera]

Hey! Thanks for the info you sent on X! ✨ I’ve been planning to make improvements to this pre for a while. Been getting info from other DIY audio enthusiasts and want to replace drain resistor with lower value to eliminate useless sub bass, and want to try installing film bypass caps to get my sparkly high frequencies back. Let me know if you have some thoughts here in the comments or shoot me an email at [e-mail] ✨ Thanks again!✨

[@thewayfarerprojectadventures]

Great editing work!

[@psycheopera]

Thanks! I'm really proud of this one : )

[@alvarobyrne]

There is a fellow youtuber who recomends wrapping the piezo in aluminum foil and connecting the aluminum foil to ground (not exactly?) in order to reduce humming, his name is metal marshmallow

[@psycheopera]

Hi! Thanks for checking out my preamp video! 😊I discovered that the humming sound was caused by issues with continuity and EMI. To fix the continuity, I reinforced the copper tape in areas where it had lifted. I also created a video that explains how I managed to reduce some of the EMI hum. Take a look at the video and let me know what you think: kzbin.info/www/bejne/hZCoqa2an9WWY5Ysi=jPhKHIV-JcOLB1eI Cheers!

[@SoyCisko]

super cool buld Keep it up 🔥🔥

[@psycheopera]

Thanks, will do!

[@hoidoi62]

Hello. I build this preamp a few days ago and it works fine. I'm using two 20mm Piezos parallel for a acoustic guitar but there is a little to much bass and a little less treble. What can i do to fix this ? Regards from Germany

[@psycheopera]

Hi! 😃 I had the same problem with my preamp. The solution is to install a passive high pass filter to the output of your preamp. I produced a tutorial about how to build a simple two to four component HPF: kzbin.info/www/bejne/sHm8cmCMmZuBoa8si=QmVLe_fAuMPkDL8P Regarding the low treble: I've been researching this issue and have found some articles and forums that suggest that short cable runs from the piezo to the preamp helps to preserve high frequencies. If this is accurate, then an external pre like ours is natively high-frequency deficient. I plan to build a cbg with an internal pre to see if this information is correct. I will, of course, produce a video to show my findings. Thank you for your questions! I hope this was helpful. Cheers! -Dr. Liza Seigido ✨😀

[@pierpa_76pierpaolo]

Transistor N FET !!! I don't have any available at the moment but I will try this circuit with a mosfet. Different or better yield ? How many dB gain does this scheme have ? Thank you very much.

[@psycheopera]

Hi! Thank you for checking out my video!😀 While I don't have an answer to your question, you can gauge the gain results by scrubbing to the 12:30 minute mark- where I present comparison recordings in my DAW. This pre is definitely worth building, however, there are sub-bass and frequency balance issues you should be aware of before starting your build. You may want to tackle these issues at the onset rather than revise your circuit later, which I'm currently doing. I've created a post outlining the changes I plan to make: kzbin.info/door/4OMtVX9uQzowxCLQWqcaQgcommunity?lb=Ugkx6FE7jb1gS_WIJQ-wmj13Gfi_-8qJr3Lb Please take a look and feel free to share any experiences, insights, or research about improving this piezo pre. Cheers!✨

[@metalmarshmallowllc]

Nice work!

[@psycheopera]

Thank you! Cheers!

[@mus2140]

Super great video! Thanks for this!

[@psycheopera]

My pleasure! ✨💜

[@codelicious6590]

I love seeing all of us auro-didacts roaming youtube and ever refining and specializing our levels of DIY. If only we could figure out how to manage it all without Amazon! Lol

[@psycheopera]

Yes, indeed. We perpetual students have created quite a nice community here in the "university of KZbin." LOL! I've learned more here from fellow tinkerers than from any brick-and-mortar institution. Sadly, it's hard for artists on a budget to avoid Amazon. But, at least for creators, they offer up the chance to earn from our art. Anyway, thank you for checking out my video. Happy New Year!

[@fmphotooffice5513]

Those traces on the PCB are ideal for simple perfboard solder tracing. It would make the final circuit tiny in comparison to your tape version. It would probably fit in a grounded Altoids box to minimize the hum too. Good luck.

[@psycheopera]

Hi! Thanks so much for the tip 👍I’ve collected a lot of small tin cigar boxes; that would be a great use for them 🤩 Cheers! 🥂

[@musicmikehere]

Cool will this work for a bass guitar, I am looking for something with no buzz or hum for my build.

[@psycheopera]

Hey there! Thank you for watching my video!😀 As for your questions, I need to split my answer into three parts so that you have all the information necessary for a successful build: 1. This pre will work with your bass guitar's piezo pickup. 2. After I built my pre, I noticed a faint hissing sound, which I later discovered was caused by a continuity issue and not by the components themselves. I found that some of the copper tape had become loose from the board. To fix the problem, I reinforced the copper lanes that had lifted off the board. The pre was noiseless after I made this fix. 3. There are frequency balance issues you should be aware of before starting your build. I recently learned that the electrolytic capacitors in the preamp cut out a lot of high frequencies, and this can reduce the bite and punch of your bass. I'm researching bypass film capacitors to preserve the high frequencies that pass through the preamp. I created a post outlining the changes I plan to make and test: kzbin.info/door/4OMtVX9uQzowxCLQWqcaQgcommunity?lb=Ugkx6FE7jb1gS_WIJQ-wmj13Gfi_-8qJr3Lb I will absolutely produce a video after I update my preamp, and I hope you'll stick around for my new piezo preamp update video. I hope this was helpful. Cheers! ✨

[@magnificenthonky]

This is a cool project. You know, though, those components are all small enough, you could have assembled all of that into the CBG. I doubt that the effect on resonance would be very noticable. And, of course, that way, you end up with one less thing to cart around with you. Again, cool project 👍

[@psycheopera]

Hi! Thanks for checking out my preamp video🤩 i’m planning to make some improvements to this preamp that will fix its sub-bass and low treble issues. I think once I get the perfect frequency balance from the circuit, I’ll start integrating them into future builds✨👍 I have some information about the changes I want to try in my community posts. Check them out and let me know what you think. ✨

[@magnificenthonky]

@@psycheopera Sounds good 👍 I'm sure you'll come up with something workable, that achieves the sound that you're looking for. I've been watching a lot of CBG builds lately, as I've recently decided to build a few, myself. Have you considered winding your own pickup coils, just to try it? That's a project that strikes me as something that you have the skillset to do. You've done some impressive things, on this channel. It's been a pleasure and an inspiration, watching you work.

[@psycheopera]

Hi! I'm honored that you are enjoying my videos; that means the world to me!✨😊 Please document your CBG builds, and feel free to share links here in my comments section. I and others would truly like to check out your work. I've stayed away from magnetic pickups for "philosophical" reasons--I don't want a clean electric guitar sound. I want to hear the individual, albeit gritty and imperfect, character of my CBGs. Although, as a crafting and audio electronics project, it would be cool to build my own magnetic pickup. I will definitely consider it.

[@guitarman_3693]

sorry to cut in the thread, but my eyes heard "magnetic pickup tranducer" for CBG -3 string. ive built three (well four but: 1 fail, i used scrap wood from cabinet shop during my lunch break & fab'ed a mahogny neck-thru maple1/4" ply body w/walnut trim or "body binding" 14° angled headstock, walnut fretboard & bridge. it was built quickly & looked good till, at home i was ready to use my 316L stainless steel, 5/32" DIA, TIG welding filler rods as fretwire, here is the funny part, I HAD NEVER ESTABLISHED A SCALE LENGTH, i just eyeball'ed it😂) 3 playable CBG's so far and 1st one had a salvaged tuners & 'bucker wired strait to TS jack, from parts 6 string & it's thickness caused me to have extra high action, my fix was wood burned faux fret wire & slide, it played ok. 2nd i opted to get some frets & a flat - pup from "Gitty" , tuneing machines from amazon. while i focused on this 25"SCALE build with a camacho box, lots of nice appointments were met, but with the flat pup, i added a B100K vol. pot. im pleased with its growling voice thru a clean flat channel, ok, yeah, flat sand/level the fret board BEFORE installing frets, i was lucky and got to install them twice. 3rd build, 25" scale, with "charvel" style reversed headstock, gitty fret wire, i used a rocky patel box & it was only 3/32" thick on top & bot. , so i tried acoustic, so i kept most the soundboard area free from touching any bracing ,ect. and cut 2 Large "f" holes bookmatching them toward the neck, and covered the inside of hole with speaker cloth. it worked, but the volume & presence was below the sound of grass growing😂, i added 1/4" jack, vol. pot wired to a 25mm piezo mounted in a recess under bridge area. i gain volume, but also gained the tone of a piezo. well its play-ability is good & enjoyable , its acoustic/ele. voice? im not so happy. which brings me to the magnetic pickup. i refused to buy one & there are a ton of vids on YT. i decided to make one. and after several attempts on flat bucker & single coil, i have finally made a single coil for 3 string that works and has a decent voicing, i only bought 2 neodynium magnets & had some extra shrink wrap, i salvaged all other componets, i used 1mm magnet wire from an AC wall adapter to DC transformer, i made thin wooden bobbin top & bottom plate, had left over - 3 screws for attaching cabinet knobs. and used for pole piece slugs & i cut a blade down from a utility knife for a back plate. with screws thru both bobbin plates i left 3/8" space between for windings & superglued all that & trimmed screw ends flush at bottom plate, drilled 2 small holes to start and finish copper windings. i wrapped plenty extra thru sm. hole & started winding , battery drill with dowel rod glued to wooden piece same as back plate, 2 sided tape. i didnt count turns, i did stop and add thin layer of wood glue to hold mag. wire in place, and wind more until i filled the bobbin, it ohm'ed at appx. 5000k resistance. both ends of tiny mag. wire was in each of the sm. holes on plate. using plenty of flux and being quick to get heat off mag. wire i snipped a section of single conductor w/shield wire from an old stereo unit with copper wire, (no aluminum) and soldered it to fashion leads from pickup, superglued razor blade to bot. bobbin plate, making sure the poles/slugs touched it well. ohh. i forgot to say before i wound mag. wire that i used black electric tape to wrap the bare metal of the pole slugs, so if mag. wire got scraped , no continutity of any pole piece or pole to mag. wire. only ohm reading was the 5000k at lead ends, now back at the pickup leads i slid the correct size shrink wrap over the 2 sm. holes & a smaller one that was sized for the wire and torched it all down for strain help on lead & protection of mag.wire ends/ solder joints. i superglued the 2 neody. magnets to the razor blade plate. i offset the magnets slightly toward the end of pup to increase the flux field as that will be excited by the larger guage guitar strings, both north poles of magnets faced the same direction. then i hung it up to be sprayed with a can of semi- gloss polyurethane for a few coats over the wood & mag. wire. to protect. it sounds good at the test bench. when mounted & being subject to playing dynamics & increased resistance of pots, jacks, cables & sending signal thru EQ & other effects, i think its gonna be a "win" for me. i made a handful of attempts that failed. it was a fun learning curve that is still going. im hoping to install on my next build using a marroon colored perez carrillo box w/gold writings. (but i will probably screw it up trying to add a tremelo or something, lol 😅😂) i like the sound of magnetic pickups a lot more that the piezo sound. i suggest to yall to wind some coils & solder some wires & play with magnets... its a lot of fun !

[@psycheopera]

Hi! Thank you for sharing your CBG journey with us. A few people have suggested that I experiment with making magnetic pickups. It does sound like a lot of fun, and I may do that when I get some backlogged projects out of the way. Thanks for checking out my video! Cheers!

[@joejo6273]

Hi there Dr. Liza.......Thanks for a very informative upload....Just a quick question if I may, would this piezo preamp be sensitive enough to pick up a 1mv signal ??

[@psycheopera]

Hi! I don't think it will work with signals that weak. The output voltage of piezo pickups can run above one volt. A mic preamp circuit may be what you need. You can find a few mic pre schematics on homemade-circuits.com. Hope this helps : )

[@thewayfarerproject]

I would like to take the output of the preamp and pass it into VCV Rack through an interface and see what magic can be made.

[@psycheopera]

That would be an interesting experiment 🧪 Let’s give it a go 🤩

[@zigisg5454]

Very unusual way of making PCB :) You make traces from several pieces of copper foil, just gluing together. this make unstable and untrustworthy contacts. I would advice you to solder pieces together for good and long life contacts. Your ham problems can solve grounded metal enclosure or lining your box inside with copper or aluminum foil and connect to output jacks ground

[@psycheopera]

Thanks for the tip!✨ I installed copper lining in the enclosure and grounded it. It did help with the hum. Here's a cute video about my shielding project... I tried to make it entertaining... hope you enjoy it 😃 kzbin.info/www/bejne/hZCoqa2an9WWY5Ysi=K0qL7694nN5YHaJD

[@espennorderud5205]

Really interesting project! I want to try this, but there's an issue: it seems hard to come across the MPF-102, it's deprecated or something. I'm looking for a good FET replacement, but as an audio DIY noob, I find it a bit confusing. What am I looking for? What are the important aspects/attributes/specs to match? Any recommended other models/versions with as good or better audio performance when used in this cirquit?

[@psycheopera]

Hi! Thank you for your question.✨Long after I produced this video, MPF-102 transistors became available on Amazon. I made an Amazon affiliate link available in the video description box.👍 I’ve not tried other MOSFETs with this circuit, but that would be an interesting project to document here on KZbin. ✨I’m planning to make some improvements to this circuit’s frequently balance by adding and switching out some components. I have all the details in my community posts; check them out and let me know what you think.👍💜✨

[@flamencoprof]

Interesting. Is there any more air-transmitted technique to incorporate in such an instrument? In my to-do list is "Create a better acoustic pickup than Piezo". Most of the acoustic guitar recordings I have heard have a distinctive sound if they are plugged in with a piezo pickup, as opposed to just being miked in the room/stage/studio. I haven't done more research yet, which is why I will save this for reference. I think just picking up the vibes of the wood does not reflect (ha-ha) what is bouncing around inside the box, nor what is coming out of the front, nor the direct sound of the strings that never enters the box. Maybe I think too much, maybe not enough :-)

[@psycheopera]

Hi! Those are definitely interesting questions.✨ The best recordings I’ve produced with these instruments involved mixing the piezo preamp output with the output of a pencil condenser placed a few inches away from the box. Here’s the video with those recordings; let me know what you think 👍 kzbin.info/www/bejne/bZ-bqmCkfdCngLMsi=HGMT_cMpdAKzZYx9

[@flamencoprof]

​@@psycheopera Thanks for your amazingly prompt reply! At that video, my unfortunately old and high-cutoff ears still found the 04:36 Piezo Preamp Recording section less to my liking than the 05:30 Rode NT5 Recording, which had a brighter sound (even I could hear :-) that better captured the box's acoustic character. The combination was nice as a recording. I guess it is a question of whether the aim is solely to capture an instrument or create a sound of interest with the instrument. I'm old and tolerant enough to find both admirable aims. It is nice to hear someone so invested in this subject and I wish you well. Try a diddley bow next :-)

[@psycheopera]

Hello again!✨ I've recently started experimenting with Diddley bows. It's been challenging for me to get into them because they are harder to play than 3-string sliders. I need to work on my rhythm and picking to get better at playing the diddley bow. I have a video about my first two diddley builds. The instruments sound different due to their shape and piezo placement. You can achieve interesting and unusual sounds when you play around with piezo placement. Anyway, here's my little diddley bow video. I hope you enjoy it! kzbin.info/www/bejne/h6LHnJ-anqt0oLMsi=PfOBY_MEmlu4S9bL

[@flamencoprof]

@@psycheopera Oh dear, my joke fell flat. My intention was to reference something much more primitive. See en.wikipedia.org/wiki/Diddley_bow

[@psycheopera]

Thanks for the link!✨Yeah diddley bows have an interesting history. I've seen some built from the side of a shed or house. Love it 🔥

[@MaddMystro]

Hi, I am building a CBG with dual pickup mag/peizo. Would the output of this preamp be sufficient to mix directly with a humbucker?

[@psycheopera]

Hi! That is a good question.✨ I've seen some cool videos by Dell Pucket where he sums the signals of piezo and magnetic pickups in his guitars. I don't remember if he's using built-in preamps with his piezos before the signals are summed. I would check out his channel; he has experience with what you want to do. Here's a link: www.youtube.com/@PuckettCigarBoxGuitar Thank you for stopping by my channel! Let me know if you get an answer to your question. 👍

[@MaddMystro]

Thank you. Very helpful. One other question, if I were to replace the 220k resistor with a 250k log pot, would this give me a volume control?

[@psycheopera]

Hi! That would be my best guess, but I don't know for sure. I'd have to breadboard it to give you a positive answer. If you decide to give it a shot, let me know if it works.

[@KPsTboy]

Maybe a silly question, but how did you know you need 50V capacitors?

[@psycheopera]

Hi! Thank you for your question. It's not silly at all. I did not select the capacitors for this build myself. Rather, I followed the schematic provided by Colin's Lab and Homemade Circuit's website. If you're interested in learning more about this circuit, both resources are linked in the video description box. Thanks for watching my video! Cheers!

[@geor664]

Any cap with a voltage rating above 10v will do. The 50v rating was chosen as being most available and inexpensive

[@marcmayou1422]

too much for me

[@psycheopera]

Thanks for checking out my video anyway : )

[@marcmayou1422]

I have M.S. building small circuits does not work. I can buy already assembled pick ups, but I like what you have done. Perhaps you can build some and offer for sale? Marc

[@psycheopera]

Hi Marc! Thanks so much for your suggestion! I've considered this, but I need to perfect the preamp further before I feel ok about building them for sale. As I type, I'm working on some vital improvements to this circuit, and plan to publish a video about it in a few days. Hope you'll check it out and let me know what you think : ) -Liza

[@TheScreamingFrog916]

I ordered a $9 piezo preamp with 5 band eq, and battery holder, meant to mount In guitar. but I plan to mount it in a metal box, so I can use it on a variety of projects that have piezo pickups, including my CBG. If I like it, I might mount it in my CBG, as I’m not so concerned about the acoustic sound. Best wishes for your continued success, and fun with music 😊

[@psycheopera]

Thanks for sharing! I wish you the best on your project. Let me know how it turns out ✨